This invention relates to a method and apparatus useful in offshore well drilling operations for cleaning the annular space between mud line suspension risers during and after cementing operations to assure that riser backout may be accomplished if a temporary abandonment of a well is to take place.
Federal regulations concerning cementing of the annular space between the well conductor string and drive pipe of an offshore well require that either cement slurry returns be observed at the surface of the platform or that a predetermined quantity of cement slurry sufficient to fill the annular space of the well conductor string and drive pipe near the disconnection of well equipment above the ocean floor be used. However, cement slurry contained in the annular space will typically foul-up the disconnection of well equipment above the ocean floor, such as a drive-pipe connector, so as to prevent backing out the riser if the well must be temporarily abandoned.
It is the object of the present invention to provide a method and apparatus for cleaning the annular space above the ocean floor mud line between mud line suspension during and after cementing operations so as to prevent cement slurry from setting up in normally disconnectable pipe joints, couplings or pipe connectors.